Abstract and Figures. The combination of a grinding circuit simulator with a model of ball wear in a grinding mill leads to a method to calculate, with a preselected accuracy, the makeup ball ...
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The Bond ball mill work index is one of the most commonly used grindability ... F80, P80, gpr. Units are kWh/t based on Morrell's empirical calibration. This value is used in the ... F80, P80, and gpr values to calculate Mib). It is also used in the CEET2 model (distributed by SGS) and is commonly used by people running the JK SimMet ...
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V — Effective volume of ball mill, m3; G2 — Material less than in product accounts for the percentage of total material, %; G1 — Material less than in ore feeding accounts for in the percentage of the total material, %; q'm — Unit productivity calculated according to the new generation grade (), t/(). The values of q'm are determined by ...
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Optimum ball charge in a SAG mill is a function of many factors. Some are discussed below. For a SAB or SABC circuit. In general, the higher the ball charge the higher the throughput (and fine feed helps as well). Of course, you need a bigger ball mill. But, high ball loads mean higher ball consumption in the circuit.
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Therefore, a 350hp motor is required and this in turn indicates that an 812 (8′ x 12′) Rod Mill is required. In the same way Fig. 3 indicates that an 800hp motor and a 101/214 or ′ by 14′ Ball Mill is required. Following is a condensed tabulation of the above selections. Sizing a Ball or Rod Mill
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How to Calculate Charge Volume in Ball or Rod Mill | .. To calculate grinding media charge for continuous type ball mill, M = x D2 x L Example ..
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Explain the role of ball mill in mineral industry and why it is extensively used. Describe different types of ball mill design. ... P80 = ; Calculate the mill size required to handle the desired throughput: Solution: W = 10*(1/√100 1/√100 0) kWt/t = kWh/t.
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Bond ball mill test procedure were carried out on crushed ( mm / 6 mesh) material at different screen closing sizes (300 µm, 212 µm, 150 µm, 106 µm, and 75 µm). The screening process was conducted in four sets of 12inch diameter screens for sufficient amount of time to avoid too much materials fed into the screen at one time.
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Grinding Studies. Two kinds of mills, BBM and LBM, were used to achieve the desired P 80 passing percentage of 150 μm with an acceptable range of hematite liberation (> 75%) at optimum grinding time. The BBM is a standard ball mill having a length and diameter of 300 mm × 300 mm with smooth liner as shown in Fig. rotating drum is attached to a gearbox and has adjustable speed knob.
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For a great presentation on How to Interpret Particle Size Distribution Data D50 D80 D90 and D10 you need to see https:// ...
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INTRODUCTION The energy consumption for grinding, according to Bond (1961), is deter mined by the formula: / 10 10 (I) The work index is determined by grinding experiments carried out in a labo ratory Bond ball mill. Based on the results of grinding experiments, numerical values of the work index Wi are calculated according to the formula ...
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Since there are not that many small SAG mill operations of under 2000 TPD, and most sub2000 TPD mills are built with rod mills and/or ball mills only; the upstream crusher plant needs to have sufficient crushing power to provide a P80 to grinding of typically <″ (40 mm) and often as finely crushed as <3/8″ (9 mm).
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In the ballandrace mill (Fig. ), balls are held between two races, much like a large ball top race or grinding ring remains stationary while the bottom race rotates. As the coal is ground between large diameter balls and the ring, the balls are free to rotate on all axes and therefore remain spherical.
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8 years ago We control the density by adding water to the feed box or usually pump pressure adjustment. Cyclone overflows gravitates straight on to the flotation roughers. Yes I am saying that at higher densities like 37slurry pulp density Vs 7 (+150um sieve density), you get P80 of 85%.
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Wash weighed sample gently through required screen into a clean bucket, using cool tap water, gentle spray and your hands until water runs clean into bucket. Filter the plus product remaining in the screen. Place the filter paper in the oven to dry. Remove to cool. Filter and dry the minus product collected in the bucket.
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P = size in microns of the screen opening which 80% of the product will pass F = size in microns of the screen opening which 80% of the feed will pass When the above equation is used, the following points should be borne in mind: The values of P and F must be based on materials having a natural particle size distribution.
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P80 Product Size 70% minus 200 mesh (75 microns) Ore's Bond Work Index Circulating Load 400% Ball Mill Power 800 HP. ... The solids content of the ball mill discharge is controlled by a ratio control loop, whereby barren solution addition is proportional to the ball mill feed. The set point of the controller is the percent solids desired ...
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particle size. A grinding mill needs a classifier to extract the particles that have been milled sufficiently finely, and to send oversize particles back to the mill for further grinding. A cyclone does this, with the cyclone overflow being the mill final product, and the underflow reporting back to the mill feed. This
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For a rod millball mill circuit, do not apply a mill diameter correction for the ball mill. If the rod mill feed is produced by open circuit crushing, use a factor of for the rod mill stage only. If the rod mill feed is 80% passing 12 mm or less ( from a closed circuit crusher) do not apply a rod mill efficiency factor.
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One can argue the f50 is a more realistic value since balls wear and the average ball size might be closer to half the maximum. Then the multiple would be closer to 13 times the maximum particle size fed to the ball mill. A f80 = 6 mm would need a ball size of 75 mm. An empirical model from "Emerging Trends in Mineral Processing", 2005, is ...
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The approximate horsepower HP of a mill can be calculated from the following equation: HP = (W) (C) (Sin a) (2π) (N)/ 33000. where: W = weight of charge. C = distance of centre of gravity or ...
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A particle size distribution indicates the percentage of particles of a certain size (or in a certain size interval). These intervals are also called size classes or fractions. A simple example is shown below. Here, a mixture of grinding balls has been separated by size: 5 mm, 10 mm, 15 mm and 40 mm: 5 mm. 10 mm. 15 mm.
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The ball mill is most often closed over a classifier like a hydro cyclone ... Typically grinding circuits that employ ball mills will produce a P80 in the range 200400 μm while the rod mill typically produces a P80 in the range 500 to 800 microns. At the top end of the product size distribution this rod mill circuit produces a P98/99 of ...
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The desired P80 (150 μm) with an acceptable range of hematite liberation (> 75%) was obtained in the laboratory ball mill after reducing 6 min from the total retention time taken in the Bond ball ...
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This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six mesh or finer feed ore samples. These equation application methods are used to process <1/2″ ore samples in a Ball Mill using a standard ball charge.
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The work index was calculated to be KWh/t using the following equation: 9 . .D BC 10 10 G I D F FHD Where: F80 is the size in microns at which 80 percent of the new feed to ball mill passes P80 is the size in microns at which 80 percent of the last cycle sieve undersize product passes Pi is the sieve opening in microns
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The formula for calculating the specific power of mill: E = w i ( 10 / √ (P80) 10 / √ (F80)) Where: E = Specific Power of Mill. w = Work Index of Ground Material. P 80 = 80% Product Size. F 80 = 80% Feed Size. Let's solve an example; Find the specific power of mill when the work index of ground material is 10, the 80% product size is ...
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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